1. Field of the Invention
The present invention relates to integrated circuits and, in particular, to the heat transfer from an electric resistor trace of the integrated circuit to the substrate.
2. Description of Prior Art
In semiconductor industry, resistors are increasingly integrated in integrated circuits as passive elements. These resistors are required to be firstly very precise, secondly as small as possible and thirdly they are required not to heat up themselves and the surrounding traces and systems beyond a specified range of temperature.
In order to meet these requirements, resistors presently used in integrated circuits have large-area dimensions or take up a large chip area, respectively, so that the heat can be readily dissipated downwards to the substrate usually made of silicon. Due to the increasing miniaturization in the field of integrated circuits these space requirements must be reduced.
The problem of heat dissipation is aggravated by the fact that in industry, due to the high requirements for the precision of the integrated resistors, the integration of these resistors in polysilicon which, due to its vicinity to the substrate material silicon, has a good heat dissipation to the substrate, is given up and for example more precise TaN metal resistors having a larger spatial distance to the silicon are adopted so that the heat dissipation to the substrate is considerably worse.
Consequently, there is a demand for a heat dissipation concept for resistor traces in integrated circuits which satisfies the high requirements for precision, miniaturization and temperature.